Fix typo in text search error path and variable bug in double casting

[lomesh2312]

Fixes #15848

Changes

This PR fixes two bugs:

1. Fixed typo in lib/schema/operators/text.js

• Changed '.$castSensitive' to '.$caseSensitive' on line 31
• Ensures error messages correctly reference the $caseSensitive field

2. Fixed variable reference bug in lib/cast/double.js

• Changed BSON.Double.fromString(val) to BSON.Double.fromString(tempVal) on line 37
• When casting objects with valueOf()/toString() methods, the extracted string value should be used instead of the original object

Testing

All existing tests pass:

• ✅ 3968 tests passing
• ✅ Text search tests verified
• ✅ No regressions introduced

Diff Summary

lib/schema/operators/text.js:

- path + '.$castSensitive');
+ path + '.$caseSensitive');

lib/cast/double.js:

- coercedVal = BSON.Double.fromString(val);
+ coercedVal = BSON.Double.fromString(tempVal);